Bubble machine



FIG. 1 is a front, right side, top perspective view of a bubble machine showing our new design;

FIG. 2 is a front, left side, bottom perspective view thereof;

FIG. 3 is a front elevational view;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.

The dashed lines are included for the purpose of defining the boundaries of the unclaimed areas of the bubble machine and depicting unclaimed features contained within these boundaries. 

CLAIM The ornamental design for a bubble machine, as shown and described. 